Ethanol extract of Verbena officinalis alleviates MCAO-induced ischaemic stroke by inhibiting IL17A pathway-regulated neuroinflammation

BACKGROUND

The prevention and treatment of ischaemic stroke is a worldwide challenge, and effective clinical treatment strategies are lacking. Studies have demonstrated the efficacy of Verbena officinalis in managing cerebrovascular disorders. However, the neuroprotective bioactive components and mechanisms remain unclear.

PURPOSE

To investigate the pharmacological combinatorial components and mechanism underlying the anti-ischemic stroke effect of the ethanol extract of Verbena officinalis (VO Ex).

STUDY DESIGN AND METHODS

The components of VO Ex were identified by HPLC. A middle cerebral artery occlusion (MCAO) induced brain injury model was used to assess the therapeutic effect of VO Ex. The activity of the chemical components of VO Ex was evaluated using a primary astrocyte injury model induced by oxygen-glucose deprivation/reperfusion (OGD/R). RNA sequencing was used to reveal the potential targets of VO Ex against cerebral ischemia-reperfusion injury (CIRI), and the results were verified by qRT-PCR and western blotting. The key components and target binding ability were predicted by molecular docking. Finally, the mechanism of combinatorial components was verified by experiments.

RESULTS

The HPLC results indicated that the main ingredients of VO Ex were hastatoside, verbenalin, acteoside, luteolin, apigenin and hispidulin. In vivo experiments showed that VO Ex improved MCAO-induced acute cerebral ischemic injury. Transcriptomic data and biological experiments suggested that VO Ex exerted therapeutic effects through IL17A signalling pathways. The in vitro experiments indicated that verbenalin, acteoside, luteolin, apigenin and hispidulin exhibited neuroprotective activities. The novel formula of VALAH, derived from the aforementioned active ingredients, exhibited superior efficacy compared to each individual component. Molecular docking and mechanistic studies have confirmed that VALAH functions in the treatment of ischaemic stroke by suppressing the activation of the IL17A signalling pathway.

CONCLUSION

This work is the first to reveal that VO Ex effectively inhibits the IL17A signaling pathway and mitigates neuroinflammation following ischemic stroke. Moreover, we identified the novel formula VALAH as the bioactive combinatorial components for VO Ex. Further research suggests that the activity of VALAH is associated with IL17A-mediated regulation of neuroinflammation. This finding provides new insights into the efficacious components and mechanisms of traditional Chinese medicine.

Metabolic Profiling by GC-MS, In Vitro Biological Potential, and In Silico Molecular Docking Studies of Verbena officinalis

Verbena officinalis L. is a traditionally important medicinal herb that has a rich source of bioactive phytoconstituents with biological benefits. The objective of this study was to assess the metabolic profile and in vitro biological potential of V. officinalis. The bioactive phytoconstituents were evaluated by preliminary phytochemical studies, estimation of polyphenolic contents, and gas chromatography-mass spectrometry (GC-MS) analysis of all fractions (crude methanolic, n-hexane, ethyl acetate, and n-butanol) of V. officinalis. The biological investigation was performed by different assays including antioxidant assays (DPPH, ABTS, CUPRAC, and FRAP), enzyme inhibition assays (urease and α-glucosidase), and hemolytic activity. The ethyl acetate extract had the maximum concentration of total phenolic and total flavonoid contents (394.30 ± 1.09 mg GAE·g^-1 DE and 137.35 ± 0.94 mg QE·g^-1 DE, respectively). Significant antioxidant potential was observed in all fractions by all four antioxidant methods. Maximum urease inhibitory activity in terms of IC₅₀ value was shown by ethyl acetate fraction (10 ± 1.60 µg mL^-1) in comparison to standard hydroxy urea (9.8 ± 1.20 µg·mL^-1). The n-hexane extract showed good α-glucosidase inhibitory efficacy (420 ± 20 µg·mL^-1) as compared to other extract/fractions. Minimum hemolytic activity was found in crude methanolic fraction (6.5 ± 0.94%) in comparison to positive standard Triton X-100 (93.5 ± 0.48%). The GC-MS analysis of all extract/fractions of V. officinalis including crude methanolic, n-hexane, ethyl acetate, and n-butanol fractions, resulted in the identification of 24, 56, 25, and 9 bioactive compounds, respectively, with 80% quality index. Furthermore, the bioactive compounds identified by GC-MS were analyzed using in silico molecular docking studies to determine the binding affinity between ligands and enzymes (urease and α-glucosidase). In conclusion, V. officinalis possesses multiple therapeutical potentials, and further research is needed to explore its use in the treatment of chronic diseases.

[Evaluation of different procedures for the extraction of phenolic compounds from a medicinal plant: Verbena officinalis]

Since ancient times, plants have been the main source of bioactive molecules, such as phenolic compounds, capable of remedying various diseases. However, polyphenols' content and efficiency vary greatly as a function of several intrinsic and extrinsic factors. To optimize the procedure for the extraction of active molecules from the medicinal plant Verbena officinalis, effects of the plant origin, selected solvent, and extraction method were assessed. V. officinalis aerial parts were collected in two different regions of Tunisia (Bizerte and Ain Draham), and their bioactive molecules were extracted by maceration, decoction, and by the Soxhlet apparatus, either with water or with ethanol. Significant variability in the extracts' contents of phenolic compounds as well as their antioxidant and antimicrobial capacities were noted depending on the different studied factors. In particular, ethanol extracts were found to generally contain higher concentrations of phenolic compounds and more potent antioxidant capacities than water extracts. However, when tested against various pathogenic bacteria, water extracts were most often at least as active as ethanol extracts to inhibit bacteria growth in vitro. Finally, differences were also observed between V. officinalis samples from Bizerte compared to Ain Draham area. All of these results emphasize the need of adapting various parameters for the optimal extraction of bioactive molecules from a medicinal plant such as V. officinalis.

Verbena officinalis Verbenaceae (Lamiales): a new plant model system for phyllotaxis research

Phyllotactic diversity and developmental transitions between phyllotactic patterns are not fully understood. The plants studied so far, such as Magnolia, Torreya or Abies, are not suitable for experimental work, and the most popular model plant, Arabidopsis thaliana, does not show sufficient phyllotactic variability. It has been found that in common verbena (Verbena officinalis L.), a perennial, cosmopolitan plant, phyllotaxis differs not only between growth phases in primary transitions but also along the indeterminate inflorescence axis in a series of multiple secondary transitions. The latter are no longer associated with the change in lateral organ identity, and the sequence of phyllotactic patterns is puzzling from a theoretical point of view. Data from the experiments in silico, confronted with empirical observations, suggest that secondary transitions might be triggered by the cumulative effect of fluctuations in the continuously decreasing bract primordia size. The most important finding is that the changes in the primary vascular system, associated with phyllotactic transitions, precede those taking place at the apical meristem. This raises the question of the role of the vascular system in determining primordia initiation sites, and possibly challenges the autonomy of the apex. The results of this study highlight the complex relationships between various systems that have to coordinate their growth and differentiation in the developing plant shoot. Common verbena emerges from this research as a plant that may become a new model suitable for further studies on the causes of phyllotactic transitions.

Verbena officinalis (Common Vervain) - A Review on the Investigations of This Medicinally Important Plant Species

Verbena officinalis (common vervain) is a medicinal plant species widely distributed in the world and commonly used in folk medicine of different countries, including traditional Chinese medicine. Monographs on "Verbenae herba" have been included in the European Pharmacopoeia since 2008, and in the Chinese Pharmacopoeia since 1995. This work presents botanical characteristics of this species. It reviews the current knowledge of its chemical composition, which is a rich source mostly of iridoids, phenylpropanoid glycosides, phenolic acids, flavonoids, terpenoids, and essential oil. A large part of this article summarizes traditional medicinal uses and professional pharmacological in vitro and in vivo studies that prove new important applications, e.g., antioxidant, antimicrobial, anti-inflammatory, neuroprotective anticancer, analgesic, or anticonvulsant of verbena herb extracts and individual metabolites. Moreover, emphasis is put on the use of V. officinalis in the food and cosmetics industries, especially due to its antioxidant, antibacterial, and anti-inflammatory properties, and the presence of essential oil with an attractive fragrance composition. This paper also presents the state of biotechnological studies of this species.

Hepatoprotective activity of Verbena litoralis, Verbena montevidensis and their main iridoid, brasoside

ETHNOPHARMACOLOGICAL RELEVANCE

Verbena montevidensis and Verbena litoralis are plants that present morphological similarities. They are both known as "gervão" and "fel-da-terra", among other popular names, and are used in folk medicine to treat diseases related to the liver and stomach.

AIMS OF THE STUDY

The aim of the current investigation was to determine the chemical composition and evaluate the hepatoprotective properties and cytotoxicity of the methanolic and aqueous extracts of V. montevidensis, V. litoralis and their main iridoid in HepG2 cells.

MATERIALS AND METHODS

Aqueous and methanolic extracts from the dried aerial parts of V. montevidensis and V. litoralis were obtained. The methanolic extract of V. montevidensis afforded an iridoid as the main compound. The extracts and isolated compound were examined for the hepatoprotective effect and cytotoxicity in human hepatoblastoma HepG2 cells by MTT reduction and neutral red uptake methods.

RESULTS

The methanolic and aqueous extracts of both species showed the presence of iridoid and phenylethanoids as the main compounds. The iridoid brasoside was isolated and identified by spectroscopic methods. The phenylethanoid was characterized by HPLC, comparing the UV profile and retention time with an authentic sample. The results of the biological assays indicate that both aqueous and methanolic extracts of V. montevidensis and V. litoralis as well as brasoside were hepatoprotective against ethanol-induced damage in HepG2 cells. The effect can be attributed to the main compounds present since both classes are recognized for this activity.

CONCLUSIONS

Our results contribute towards validation of the traditional use of V. montevidensis and V. litoralis in the treatment of liver disorders.

Acute and subacute toxicity and chemical constituents of the hydroethanolic extract of Verbena litoralis Kunth

ETHNOPHARMACOLOGICAL RELEVANCE

Verbena litoralis Kunth is a native species of South America, popularly known as gervãozinho-do-campo or erva-de-pai-caetano. It is used in gastrointestinal disorders, as detoxifying the organism, antifebrile properties and amidaglitis.

AIM OF THE STUDY

To identify the chemical constituents of the hydroethanolic extract obtained from the aerial parts of V. litoralis and to evaluate the acute and sub-acute toxicity in male and female rats.

MATERIALS AND METHODS

The single dose (2000 mg/kg) of the extract was administered orally to male and female rats. In the subacute study the extract was given at doses of 100, 200 and 400 mg/kg during 28 days orally. Biochemical, hematological and histological analyzes were performed, oxidative stress markers were tested and chemical constituents were identified through UHPLC-ESI-HRMS RESULTS: Six classes of metabolites were identified: iridoids glycosides, flavonoids, phenylpropanoids-derived, phenylethanoid-derived, cinnamic acid-derived and triterpenes. In the acute treatment, the extract was classified as safe (category 5), according to the OECD guide. Our results demonstrated that subacute administration of the crude extract of V. litoralis at 400 mg/kg resulted in an increase in AST in males, whereas ALT enzyme showed a small increase in males that received 200 mg/kg and 400 mg/kg of the extract.

CONCLUSIONS

The extract of the aerial parts of Verbena litoralis did not present significant toxicity when administered a single dose. However, when different doses were administered for 28 days, were observed changes in hematological, biochemical and histological parameters in rats.

Short-term effects of Verbena officinalis Linn decoction on patients suffering from chronic generalized gingivitis: Double-blind randomized controlled multicenter clinical trial

OBJECTIVE

To evaluate the clinical efficacy of Verbena officinalis Linn decoction for patients with chronic generalized gingivitis in a double-blind randomized controlled multicenter clinical trial.

METHOD AND MATERIALS

The patients in the test group and the control group were instructed to brush and floss. Additionally, the patients in the test group were asked to rinse their mouths with a V officinalis L decoction. The primary clinical outcome was the Gingival Index (GI). The GI and Plaque Index (PI) were measured at baseline (day 0), day 14, and day 28.

RESULTS

Two hundred and sixty patients participated (control group = 130, and test group = 130). The clinical features of both the test and control groups were improved progressively throughout the time durations of day 0, day 14, and day 28 represented by highly significant decreases in both GI and PI (P < .001). The Mann-Whitney test revealed significant differences between the control and test groups for GI and PI at the 14-day examination and the 28-day examination (P < .001). At the beginning of the clinical trial, nonsignificant clinical differences were found following the statistical analyses of both GI (P = .981) and PI (P = .920) between the test and control groups.

CONCLUSIONS

The tested V officinalis L decoction demonstrated efficacy in reducing tested indices and thus has a promising ameliorative effect for treating patients with chronic generalized gingivitis.

CLINICAL SIGNIFICANCE

V officinalis L decoction has good clinical results with no adverse effects.

Study on in-vivo anti-tumor activity of Verbena officinalis extract

We investigated the anti-tumor effects of Verbena officinalis extract on H22 tumor-bearing mice and its effect on immune function. Mice model of H22 solid tumor was established, the mice were divided into five groups and administered the extract, later, tumors were removed and inhibition rates were calculated; spleens were removed and spleen indices were calculated, and the sheep red blood cell-delayed-type hypersensitivity (SRBC-DTH) and the serum hemolysin level were determined. The Verbena officinalis extract had anti-tumor effect, with the inhibition rate reaching 38.78%, it also increased the spleen index to a certain extent, in addition, the changes in DTA and HA were not obvious compared with the model group. The Verbena officinalis extract had in vivo anti-tumor effect, while causing no damage on the immune function.

Lemon verbena infusion consumption attenuates oxidative stress in dextran sulfate sodium-induced colitis in the rat

BACKGROUND

Inflammatory bowel diseases (IBD) consist of an uncontrolled intestinal inflammation leading to mucosal disruption. This inflammation is accompanied by an excessive production of reactive oxygen species (ROS). Polyphenols are micronutrients with antioxidative and anti-inflammatory properties, and may play an interesting role in the prevention of intestinal inflammation. Lemon verbena (Aloysia triphylla) infusion is a popular herbal infusion rich in polyphenols (flavones and verbascoside).

AIMS

This study evaluated the preventive effects of lemon verbena infusion consumption against mild-to-moderate dextran sulfate sodium (DSS)-induced colitis in rats.

METHODS

Wistar rats drank water or lemon verbena infusion for 14 days. On day 15, half of the rats received DSS (4%) in their drink for 7 days. At the end of the experimental period, the colon was taken for histopathological examination and determination of myeloperoxidase (MPO) activity, antioxidant enzyme activities (superoxide dismutase [SOD], glutathione peroxidase [GPx], glutathione reductase [GR], catalase [CAT]), glutathione and lipid peroxidation. Lymphocyte populations were determined in blood, mesenteric nodes and Peyer's patches.

RESULTS

Rats ingested daily 5.6 μmol of polyphenols. DSS reduced food intake and induced colitis, as reflected by histological lesions and increased MPO activity. Although these alterations were not significantly counteracted by lemon verbena consumption, the herbal infusion increased colonic SOD activity and decreased lipid peroxidation (malondialdehyde). Other oxidative stress markers (GPx, GR, CAT, glutathione) were not significantly modified.

CONCLUSION

Our study shows that the preventive consumption of lemon verbena infusion offered some antioxidative protection during experimental colitis by stimulating SOD activity and decreasing lipid peroxidation.

Effects of differential extraction of Verbena officinalis on rat models of inflammation, cicatrization and gastric damage

Verbena officinalis L. is used in folk medicine for the treatment of inflammatory disorders, skin burns, abrasions, and gastric diseases. Extracts obtained with different solvents (methanol, VoME; enriched flavonoids, VoEF; supercritical CO2, VoCO2) were evaluated for anti-inflammatory, gastroprotective and cicatrizing activities. Additionally, the antioxidant capacity was determined in vitro. In order to confirm the activities investigated, histological observations were performed. All extracts induce a remarkable anti-inflammatory activity. The gastric damage is significantly reduced by all extracts administered, whereby the most pronounced protection is observed for the VoCO2 and VoEF extracts. Finally, a wound healing effect is obtained particularly by the CO2 extract, suggesting the presence of some lipophilic active principles. Histological evidence confirms the results evaluated with the animal procedures. The results obtained after oral administration of V. officinalis extracts are also in agreement with the antioxidant capacity evaluated in vitro, confirming the relationship between pharmacological activities and antiradical efficacy.

Anti-inflammatory and analgesic activity of the topical preparation of Verbena officinalis L

Verbena officinalis has traditionally been used in herbal medicine in Navarra, Spain, in the treatment of topical inflammation. Due to the anti-inflammatory activity of Verbena officinalis 50% methanolic extract in i.p. and topical administration, the effects of several formulations were prepared and studied using carrageenan-induced edema and formalin testing. Piroxicam gel and methyl salicylate ointment were studied as positive control for anti-inflammatory and analgesic activity, respectively. The edema inhibition of the preparations containing extract at the doses of 1-3% w/w were significantly different from the control group. The anti-inflammatory effect of VO-3% was similar to the effect of piroxicam gel 3 h after carrageenan injection. The analgesic activity of topical preparation with more than 2.5% w/w was observed in the early phase. This activity was observed in concentrations of more than 2% w/w in the late phase. The topical analgesic activity of the extract was less than the analgesic activity of methyl salicylate ointment.

Pathogenicity of the Entomopathogenic Fungus, Lecanicillium muscarium, against the Sweetpotato Whitefly Bemisia tabaci under Laboratory and Glasshouse Conditions

The potential for using the entomopathogenic fungus Lecanicillium muscarium to control the sweetpotato whitefly, Bemisia tabaci has been established in the laboratory by other studies. Laboratory studies however frequently overestimate the level of control achieved by biological control agents in the glasshouse. Before full-scale commercial or field development is considered, glasshouse trials are required to confirm laboratory results. Under both controlled laboratory and glasshouse conditions high mortality of second instar B. tabaci was recorded after application of L. muscarium. The potential of incorporating L. muscarium into integrated pest management strategies for the control of B. tabaci is discussed.

Management of insomnia: a place for traditional herbal remedies

(1) Insomnia should be treated first with non drug measures; this has traditionally involved the use of herbal remedies. (2) About 20 plants are approved in France in the production of medications 'traditionally used' for minor sleep disturbances. Virtually nothing is known of their efficacy or potential dangers. (3) Most of these plants are suspected of toxicity and should therefore be avoided, especially in view of their unproven efficacy. (4) Littleleaf linden, vervain, melissa and orange flower have no demonstrated efficacy but are safe and can therefore be used. Similarly, there are no scientific grounds for rejecting preparations based on hawthorn or passiflora. (5) Available data suggest that valerian extracts have a modest impact on subjective sleep quality; they are nevertheless more effective than a placebo. Valerian products that do not contain valepotriates have no apparent adverse effects. It is best to avoid high-titre alcoholic extracts and powdered valerian root, and to select aqueous extracts and low-titre hydro-alcoholic preparations.

Citral is a new inducer of caspase-3 in tumor cell lines

Citral, 3,7-dimethyl-2,6-octadien-1-al, a key component of the lemon-scented essential oils extracted from several herbal plants such as lemon grass (Cymbopogon citratus), melissa (Melissa officinalis), verbena (Verbena officinalis) is used as a food additive and as a fragrance in cosmetics. In this study, we investigated the anti-cancer potential of citral and its mode of action. Concentrations of 44.5 muM, comparable to the concentration of citral in a cup of tea prepared from 1 g of lemon grass, induced apoptosis in several hematopoietic cancer cell lines. Apoptosis was accompanied by DNA fragmentation and caspase-3 catalytic activity induction. Citral activity (22.25 microM) was compared to a reference compound like staurosporine (0.7 microM), in respect to DNA fragmentation and caspase-3 enzymatic activity. The apoptotic effect of citral depended on the alpha,beta-unsaturated aldehyde group.

The susceptibility of immature stages of Bemisia tabaci to the entomopathogenic fungus Lecanicillium muscarium on tomato and verbena foliage

Lecanicillium muscarium is a widely occurring entomopathogenic fungus. Laboratory studies were conducted to determine the efficacy of L. muscarium against different instars of Bemisia tabaci on tomato and verbena foliage after two incubation times (3 and 7 days). Significant reduction in B. tabaci numbers were recorded on fungus treated plants (p < 0.001). Second instar B. tabaci proved most susceptible to L. muscarium infection. There was no significant difference in mortality of B. tabaci second instars after either 3 or 7 days exposure to L. muscarium on either host plant. The importance of the speed of pest mortality following treatment and the potential of L. muscarium to be incorporated into an integrated pest management strategy for the biocontrol of B. tabaci on tomato and verbena plants are discussed.

Littorachalcone, a new enhancer of NGF-mediated neurite outgrowth, from Verbena littoralis

A new dihydrochalcone dimer, 2',4',3",2"',4"'-pentahydroxy-4-O-4"-tetrahydrobichalcone, given the name littorachalcone, was isolated from the aerial parts of Verbena littoralis H. B. K. along with two known flavonoids 4'-hydroxywogonin and 8,3'-dimethoxy-5,7,4'-trihydroxyflavone. Littorachalcone caused a significant enhancement of nerve growth factor-mediated neurite outgrowth from PC12D cells.